Simplify the following expression: ${p-3-6+2p}$
Explanation: Rewrite the expression to group the ${p}$ terms and numeric terms: $ {p + 2p} {-3 - 6}$ Combine the ${p}$ terms: $ {3p} {-3 - 6}$ Combine the numeric terms: $ {3p} {-9}$ The simplified expression is $3p-9$